Gold nanoparticle photosensitized radical photopolymerization

We report the photopolymerization of an acrylic monomer using thiol-stabilized gold nanoparticles (AuNPs) and [4-[( octyloxy) phenyl] phenyl] iodonium hexafluoroantimonate (OPPI) as photoinitiator and coinitiator, respectively. Polymerization occurred only when the AuNPs, in the presence of the iodonium salt, were irradiated at the particle plasmonic absorption region (lambda > 450 nm). The AuNPs activate the coinitiator by intermolecular electron transfer since OPPI has no absorption in the visible region. Fourier transform infrared spectroscopy was used to monitor polymerization. UV-Vis spectroscopy and transmission electron microscopy measurements were used to characterize the NPs.